Distance-finder.



W. L. FRY.

DISTANCE FINDER.

APPLICATzoN man SEPTJI. 1912. RENEWED APR.20,1915.

Llg Patented Dec. 7; 1915.

. 2 sHfETs-sHEsT1- W. l.. FRY.

DISTANCE FINDER.

APPLICATION FILED sEPT.21,1'912. RENEWED 11911.20, 1915.

1,163,594. Patented De.7,1915.

2 SHEETS--SHEET 2.

weimar. L. rar, ornnw Yoan, vn.. Y.

DISTANCElFINDER.

Specification of Letters Patent.'

Patented Dec. 1915.

Application filed September 21, 1912, Serial No. 721,683. Renewed April 20, 1915. Serial No. 22,714.

To all whom t may concern.'

Be it known that I, WALTER L. FRY, citizen of the United States of America,- and a resident of New York city, county and State of New York, have invented certain new and useful Improvements in DistanceFinders, of which the following is a specication.

My invention relates to distance finders for photographic cameras, and comprises the combination withan image-forming viewnder, of means comprising a gravity-operated member for indicating the distance `from the camera of the object to be photo- 4 The objects of my invention are, to provide anv improved distance iinder for photographic cameras which may be used with greater facility than the devices for the same purpose heretofore used, and which drawings, andwill then point out the novel features in claims. y fIn the said drawings Figure 1 shows a side view of a photographic camera, Fig. 2

shows. a plan view of the view .finder of that camera with the distance finder attached, Fig. 2 shows a vertical section of the view finder through the optical axis thereof, Fig. 3 a diagram illustrating the, principle of operation of the distance finder,- Fig. i an axial Section of one form ofthe distance finder, Fig. 5 a"transverse section of such finder, and F ig. 6 a top view of such inder,'Fig. 7 a side view of an alterna-tive form of the distance finder, and Fig. 8 an axial section thereof, Fig. 9 a side view of a further alternative form of such distance* finder, andF ig. 10 a side ,view of another alternative form of such distance finder.4 Fig. 11 shows' on an enlarged scale, a side velevation of a photographic View finder pro-y vided wi'th a further alternative form of distanceI finder, the cover of the view finder being shown in section. Fig. 12 shows a top view of the distance'finding attachment to the view finder illustrated in Fig. 11, and Fig. 13 shows an end view of such distance finding attachment. Fig. 14 shows an eler vation of a camera provided with a further alternative form of distance finder operating upon the principle ofthe well known spirit level, l5 shows a top view of such disview finder, and Fig. 20 a detail sectionall View of such View finder, showing also the distance finding attachment.

Referring to the drawings, and at first to Figs. .1 to 6 inclusive, l designates the camera. itself, which camera may be of any of the usual constructions; 2 designates the view finder of such camera-rt the objective lens thereof, 4 the relectorji'ereof and 5 the image lens thereof, and vl'designates the distance finder itself. In the construction shown in Figs. 4, 5 andl 6, this distance.

finder comprises a substantially cylindrical case 7 having a sight opening 8 in the top thereof andhaving within it a pendulous weight 9 supported onfan arbor 10, and having secured to it a gear sector 1l intermeshing with a pinion 12, itself secured to a flanged disk 13, Such` disk having an opening 14 for the passage of the arbor 10, which opening permits the vflanged disk 13 to swing through a considerable angle without interference with the arbor 10. The sight opening 8 in case 7 is provided' with a transparent plate 15, across the center of which is. marked, 1n any suitable manner, a center line 16. The outer surface of the flange of g the disk 13 is provided with suitable graduations indicating angles, and therefore, as will. be seen hereafter, indicating distances. The case 7 is further provided with a spring clip 17 for attachment of the distance finder to the view finder 2 of the camera. ASuch view finders customarily are provided with a swinging light shield 18, which light shield, when the finder is, in use, is turned upward as indicated in Fig. 1,and the spring clip 17 is adapted to engage ,the inner surface of one side, of the light shield 18, resting upon the top surface 19 of the view finder, as shown vparticularly in Fig. 2.

The action of the distance finder will be understood by referring to the diagram, Fig. 3. As is well known, hand cameras, such as the particular camera illustrated, Aare customarily held at about the waist linefofthe user, when being used. The waist height of adults, at least, varies rela-tively little as compared with the variation of stature. ln the diagram, Fig. 3, A. represents the point at which the user of rthe camera is standing, and B and B represent two points at which the bases of two objects to loe photographed may be understood to be. The line A-B is therefore a base line, which is assumed to be substantially horizontal. C designates the point atvwhich the camera is held, the line AFC being the height at which the camera is held above the base line or ground. rlhe user of the distance finder, holding the camera in the ordinary position for exposure, looks into the view finder 2, and sees on the image lens of that view finder, the object to be photographed, thereby centering the camera and the view linder, with respect to the object to be photographed. Ho then depresses the camera until the base of this ribject to be photo* graphed is at the center of the image lens of the View iinder. ,(Ci'istomarily, l provide this image lens or image plate with-a transverse center line 20, for convenience in use of the distance finder, although this is not necessary, as it is easy to judge with almost absolute accuracy, the center of the lield of the finder). ln so depressing the camera, the angle of the optical axis of' the camera is changed to the line CMB, or C-B, or some other oblique line extending from the point C to some point on the base line A-B. The angle a-AC-B or A-C-B, or other angle of depression of the camera is, therefore, a direct function of the distance of the base of the object to be photographed from the camera. in so depressing the camera., the weight 9 is caused to swing, since this weight is free to move, and hangs vertically downward, notwithstanding thc angle at which the camera may be held. Such motion of the weight) is multiplied, with respect to the flanged disk 13, by the gear ll and pinion l2, the flanged disk 13, therefore, moving through a relatively great distance, for a relatively small movement of the. weight Y). l

' As has been stated, the peripheral surface `of the flange of disk 13 is provided Awith graduations which correspond to angles of deflection of the weight 9 with reference to the center line 16. in practice, the surface of the flange of disk 13 is graduated to distances rather than to angles.4 rllhe user of the camera, having depressed the camera until the base of the object to be photographed is at the center of the finder, can immediately read upon the periphery of the 'flange of disk 13, the distance graduation which, at such ,tangle of depression of the camera, is directly beneath the center mark 16. He, therefore, can at once focus his camera for the distance so indicated, by

incense means of the usual distance scale and focus ing device with which hand cameras are commonly provided, and can then raise .the camera to bring the object to be photo graphed in the center of the finder field,`and operate the camera shutter as usual for the exposure, with reasonable assurance that the camera has been properly focused.

ln practice, to compensate for varying heights at which the camera may be held, l provide the peripheral surface of the dangeof disk 13 with a plurality of longitudinal lines 2l, and 23, corresponding to different heights at which the camera may be held, and l mark suitable distances iii-l5, fir-BQ etc., on these lines Q1, 22 and 23, according to some accepted unit of linear measurement, and l may also provide curved transverse lines connecting corresponding distance marks on the several longitudinal lines 9.1, 29. and The user of the camera will soon learn along what line 2l, or 23, (or it may be, along some imaginary line between lines 2l or 2Q, or between 9:2 and ydistances should be read by him, on the lines 24. The user of the camera will also soon learn to make such correction as may be necessary in case the base line is not horizontal; but in most lases the base line is horizontal.

l am aware that heretofore distance estimating instruments have been employed,v comprising sighting means, together with a gravitating member to indicate. angles of inclination, and therefore distance. But so far as l am aware the view finder itself of a camera has not heretofore been emploved as la sighting means for the distance ruider.

held, when determining distance, at the position ofA exposure, and since it permits finding of distance at the instant when the user has positioned the camera to bring the object to be photographed within the .field of view of the finder. Therefore, the entire operation of sighting the camera, focusin, and exposing, may be done in an instant.

The flanged disk 13 maybe provided with a convenient brake 25 for holding said hanged disk and the weight S) stationary when the distance finder is not in use, and so avoiding unnecessary wear of the parts.-

The bottom of the spring clip i7, since it rests upon the top of the finder, positions the distance finder accurately with reference lo the view finder.

Various alternative constructions of my .In the construction shown in Fig. 9, the

. pointer there designated by numeral 29a has c. gear connection with the weight there designated by numeral 27a. Y

In the form shown in Fig. 10 the connection between the pointer, there designated by numeral 29", and the weight, there designated by numeral 27h, is by means of friction-sectors 33 and 34, the pivot 28h of the weight 271 having slight clearance in a hole of disk 26,"'inwhich it is mounted, and a spring 35 being provided `for holding the surfaces of the sectors 33 and 34 in contact.

In the form otl distance finding v device shown in Figs. l1, 12 and 13the distance finder comprises a plate 36 adaptedto be slipped within the cover 18 ot' the view finder and to secured thereto by' means of spring cllps 37; andthis plate 36 is provided with 1 depending pivoted combined weight and pointer 38 adapted to move over a scale 39 provided on one surface of plate 36.

In the construction shown in Figs. 14, 15, 15 and 17, l employ a device working on the principle of the well known spirit level, and comprising a tube of transparent material 39, having within it liquid and an air -bubble 4t). Y This tube 39 is curved, and set within a frame 41, preferably secured to some suitable fixed portion of the camera, Jfor example, the camera bed 4*?. (Fig. 14) by means ot' a hihge 43, which permits the distance finding device to be turned up into proper position for action when the camera is turned on its side. The tube 39 is provided with scale graduations, as indicated particularly in Fig. 15. It will be recognized that in such a spirit tube device as shown Vin Figs.

15, 16 and 17, the liquid within the tube is a gravitating weight.

The spirit tube device may also be embodied in the view finder itself. rl'liis is illustrated in Figs. 18, 19 and 20, wherein 2 designates the view finder ot' ordinary construction, except that it is provided on one side with a recess adapted to receive a spirit tube 39 such shown in Fig. 16.

It will be recognized that my distance nder, in its various forms, beside serving finder comprising image-producing lmeans,

ofa distance finder secured in fixed relation thereto and comprising indicating means showing degree of inclination of the optical axis of such view vfinder, said view l'nder ,constituting sighting means t'ol' the distance finder, the said indicating means being visible simultaneously with the image-producing means of the view tinder.l

2. The combination with a camera viewiinder comprising reflecting image-producixed relation thereto,- and comprising indicating means showing degree or inclination of the optical axis ot' such view-finder, the view-finder constituting sighting means for the distance finder, the said indicating means being visible simultaneously with the imageproducing means of the view-nder.

3. The combination with a camera viewfinder, of a distance finder secured thereto in proximity to the image plate of such viewfinder, and comprising means visible simultaneously with the image ot' such view-inder, indicating distance of object to be photographed from such view-finder, such viewfinder constituting sighting means for the distance finder. u A '-1. rlhevcoxnbination with a camera viewfinder comprising image-producing means,

of adistance indersecured tosuch viewln testimony whereot'. l have signed thisl specification in the presence ot two subscribing witnessesa WALTER L. FRY.

Witnesses:

H.' M. lvlaunnn, D. A. Davies.

ing means, of a distance-finder secured inv 

